Augustus j



(No Model.)

v A. J.0EHR,ING.

ELECTRIC BELL No., 511,451'. Patented Dfw.A 26-1a9,3.

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FUNITED STATES PATENT OFFICE.

AUGUSTUS J. OEI-IRING, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE WESTERNELECTRIC COMPANY, OF SAME PLACE.

yELECTRICv BELL.

SPECIFICATION forming-part `of Letters Patent No. 511,451, datedDecember 26, 1893. Applicationrled April 26', 1891. Serial No; 390,475.Y (No model.)

To a/ZZ whom it may concern:

1.3@ it known that I, AUGUSTUS J. OEHRING, a cltizen of the UnitedStates, residing at Chicago,1n the county of Cook and State of Illinols,have invented a certain new and useful Improvement in Electric Bells,(Case No. 4,) of which the following is a full, clear, concise, andexact description, reference being had to the accompanying drawings,forming a part ro of this specification.

Y I My invention relates to electric bells, and its object is to arrangethe poles of the magnet with respect to the'armatu re in such mannerthat the greatest effect may be produced I5 by a given amount ofmagnetization.

Another objectV of my invention isto provlde means for holding theadjustable back contact screw in position after it is once adjusted.I-Ieretofore in this class ot bells the zo different poles of theelectro magnet have been presented to the armature at differentdistances from its pivotal point, that is, usually one above the other.Thus the pole nearest to the pivot and hence nearest to the ar- 2 5mature is most effectivein attracting the armature. The other pole beingseparated from the armature by so great a distance exerts, comparativelyspeaking, little attractive force upon the'armature. I provide an ar- 3omature of sucient width so that the different poles of the magnet whichare made narrow and about thelength verticailypf the armature may bepresented in front of the armature near the opposite edges thereof so as3 5 to act equally thereon and each'with the very greatest possiblepower. Heretofore the in-V sulated post carrying the adjustable backcontact screw hasbeen slit at the top at right an-v gles to the holetapped out for the screw form- 4o ing the adjustable back contact, andby Slightly spreading'the slot by bending and then inserting thesCrewthescrew is held in place and prevented by the tension of the differentparts of the post from working out; that is to say, the thread isslightly out of line and the tension of the parts of the post ondifferent sides of the slot therefore serves to bind the screw andprevent it from working out under the action of the spring carried upon5o the armature. I mount the back contact screw upon a piece ofinsulating material and,

a metallic spring in suchmanner that the tension of the spring willprevent the screw from working out. The insulated piece and spring aretirst riveted or otherwise secured together, 5 5 and the spring broughtin position so as to rest dat against the inner face of the piece ofinsulating material. A hole is now tapped out through the insulatingpiece and the spring at a single operationrafterward the 6c spring isbent away from the insulating piece and afterward sprung back so as tocatch the thread of the screw when the screw is turned in; the tensiongiven to this spring being bent away from the rubber piece now serves tohold the screw in position.

In casting the frame I provide thereon a lug so that one end of theretractile spring may be attached thereto.

My invention will be more readily under- 7o stood by reference to theaccompanying drawings, in which- Figure l is a front elevation of anelectric bell embodying my invention. Fig. 2 is a central sectional viewthereof. Fig. 3 is a view 75 from below. Y Fig. 4 is a side elevationshowing a portion of the frame broken away and the head of the backcontact screw inserted through apiece of insulating material. Fig. 5shows the insulating material and the me- 8o tallic spring mountedthereon and the adjustable' screw inserted therethrough. Fig. 6 is aview of the spring between the armature and the adjustable contactscrew, this spring being provided with projections for insertion throughholes which arev provided in the armature.

Like parts are indicated by similar letters of reference throughout thedierent figures.

The frame a may be a casting which is pro- 9o vided with projections orlugs for attaching the several -parts of the bell thereto. Thus thearmature b is placed upright and pivoted between lugs c and the portiond of the frame opposite said lug. The electro magnet consists vof twospools, the cores being dat and secured together at the heel upon theprojection ke of the frame. Two screws are employed for this purpose,which preferablyfpass through the heel ends of the two cores, holesbeing proroo vided for the screws in said projection e. Thus the magnetis secured in vplaceand the poles thereof presented opposite thearmature which is made Wide enough to come opposite both the poles. Theinsulating piece fand the spring g serve to support the adjustablecontact screw h. A hole for `this screw is tapped out through theinsulating piece and the spring when the spring is pressed against theinsulating piece. Afterward the spring is bent away from the insulatingpiece andwhen the screw is inserted as shown, the thread for the screwin the spring being slightly displaced by such bending away withreference to the thread in the insulating piece, the screw will be moresecurely held in position. The contact spring t' may be stamped outprovided with projections la, by means of which the contact springt' maybe readily securedto the armature. The retractil@ spring lis securedbetween the hookm of the armature or contact spring t' and the lug nprovided upon the frame.

I have sometimes employed an electro magnet having one flat core andcoil instead of two as shown. In this case one extremity ot' the fiatcore is secured to the lug e and the other is presented to the fiatarmature b. The magnetic circuit is completed through the frame of thebell; hence I do not limit myself to the employment of two cores for theelectro magnet.

Having thus described my invention, I claim as new and desire to secureby Letters Patent- 1. In'an electric bell, the combination with a pairof electro-magnets, oblong in cross section and provided with cores ofoblong cross section, said magnets occupying positions with theirgreatest dimensions parallel, of an armature pivoted to an axis at rightangles to the greatest dimensions of said magnets, substantially asdescribed.

2. The combination with the insulating piece f of the spring g attachedthereto, a hole being tapped out in said insulating piece and saidspring, an adjustable contact screw inserted through said hole, saidspring being secured to said piece f at one side of said hole and sobent to one side that the thread of said spring may be out of line withthe thread of said piece f, substantially as described.

In witness whereof I hereunto subscribe my name this 26th day of March,A. D. 1891.

AUGUSTUS J. OEHRING. Witnesses:

CHAs. A. J osLYN, Jr. F. LANCASTER.

